JP5747897B2 - Internal combustion engine control method and internal combustion engine control apparatus - Google Patents

Description

  The present invention relates to a method for controlling an internal combustion engine provided with blow-by gas recirculation means and a control device for the internal combustion engine.

In an internal combustion engine, in the combustion stroke, a slight amount of semi-combustion gas in the middle of combustion leaks from the gap between the piston and the cylinder into the crankcase due to an increase in pressure in the combustion chamber. In the internal combustion engine, blow-by gas, which is a semi-combustion gas leaking into the crankcase, is returned to the intake passage side without being released into the atmosphere and mixed with new intake air and burned in the internal combustion engine. As such, blow-by gas recirculation means is provided.
Since this blow-by gas is a semi-combustion gas, it contains water (including water vapor) and has a temperature higher than the temperature of the atmosphere.
In particular, when the temperature of the atmosphere is low, such as below freezing, in the winter season, frost and frost due to condensation form at the junction where new low-temperature intake air and blow-by gas higher than the intake air are mixed. May occur. If ice due to icing or frost accumulates, the surrounding equipment may be fixed, or ice blocks may flow downstream, which may cause malfunction of the throttle valve, turbo compressor, internal combustion engine body, etc. Therefore, it is not preferable.

For example, in the prior art described in Patent Document 1, when it is determined that the moisture in the blow-by gas piping is likely to freeze, a low-pressure EGR (exhaust gas recirculation device) that joins the blow-by gas piping is used. A blow-by gas processing apparatus for an internal combustion engine that recirculates low-pressure EGR gas from a pipe, heats the vicinity of a connection part between the blow-by gas pipe and the low-pressure EGR pipe, and defrosts ice generated in the vicinity of the connection part is described. Has been.
The prior art described in Patent Document 2 includes an electric heater in a PCV valve that controls the opening and closing of the blow-by gas piping. The electric heater is energized until the target heat amount is reached, and the PCV is not energized more than necessary. A control device for a PCV valve is described which thaws the ice produced in the vicinity of the valve.

JP 2010-285937 A JP 2009-24514 A

The prior art described in Patent Document 1 is to thaw ice using EGR gas having a temperature higher than that of blow-by gas. However, some internal combustion engines preferably do not recirculate EGR gas and are always used. It is not possible. In addition, it is essential that the blow-by gas piping and the low-pressure EGR piping be merged before the intake passage as a device configuration, and may not be physically possible in an engine room packed with multiple devices and piping. There are concerns about mounting problems.
Further, in the prior art described in Patent Document 2, since the electric heater is mounted on the PCV valve, the PCV valve is not preferable because it increases cost and size. Moreover, in order to thaw the ice produced | generated in the said confluence | merging part, it is necessary to arrange | position this enlarged PCV valve in the vicinity of the said confluence | merging part, In the engine room where several apparatus and piping were packed, There are cases where it is physically impossible, and there is a concern about mounting problems.
The present invention was devised in view of the above points, and the ice generated at the junction of the new intake air and the blow-by gas can be generated with a simpler configuration without causing a problem of mounting. It is an object of the present invention to provide an internal combustion engine control method and an internal combustion engine control apparatus capable of suppressing accumulation.

In order to solve the above problems, the control method of an internal combustion engine according to the present invention takes the following means.
The first aspect of the present invention is a control method for an internal combustion engine provided with blow-by gas recirculation means.
An intake pipe is connected to the internal combustion engine, and a blow-by gas pipe for returning the blow-by gas to the internal combustion engine is connected to the intake pipe.
An environment in which ice is generated at the junction between the blow-by gas pipe and the intake pipe based on at least the temperature of the intake air drawn from the intake pipe by the control means for controlling the operating state of the internal combustion engine An environmental state determination step for determining whether or not the engine is in a state, and if it is determined that the state is an environmental state in which ice is generated, the operating state of the internal combustion engine is changed so that the temperature of the blow-by gas increases. A forced blowby gas temperature increase step, and in the environmental state determination step, an increase or decrease in ice is predicted and predicted based on at least the temperature of the intake air. Or it is an environmental state where ice is generated when the amount of ice generation is predicted by accumulating the amount of decrease, and it is determined that the predicted amount of ice generation is greater than or equal to the predetermined amount. Determines that a control method for an internal combustion engine.

Usually, since the intake air temperature detecting means for detecting the temperature of the intake air of the internal combustion engine is already provided, it is not necessary to newly add the intake air temperature detecting means. Even if the intake air temperature detecting means is not provided, the intake air temperature detecting means is relatively small and can be easily attached to the intake pipe.
Further, since only the operation state of the internal combustion engine is changed so that the temperature of the blow-by gas rises, no EGR pipe, heater, or the like is required.
Therefore, according to the first aspect of the present invention, it is possible to suppress the accumulation of ice generated at the junction between the new intake air and the blow-by gas with a simpler configuration without causing a problem of mountability. .

In the first invention, it is possible to more appropriately realize the determination as to whether or not the environment state in which ice is generated.

Next, a second aspect of the present invention is a method for controlling an internal combustion engine according to the first aspect of the present invention, wherein the increase or decrease amount of ice in the junction is predicted in the environmental state determination step. The control method of the internal combustion engine predicts based on the temperature of the intake air and the temperature of the blow-by gas, or the temperature of the intake air, the speed of the vehicle, and the shift speed of the vehicle.

In the second aspect of the invention, the amount of increase or decrease in ice at the junction can be predicted more appropriately.
In general, the intake air temperature detection means, the vehicle speed detection means, and the vehicle gear position detection means are often provided, and the detection means that needs to be newly added is the blowby gas temperature detection means. The temperature detecting means is relatively small and can be easily attached to the blow-by gas pipe.
Therefore, it is possible to suppress the ice generated at the junction of the new intake air and the blow-by gas from being accumulated with a simpler configuration without causing the problem of the mountability.

Next, a third aspect of the present invention is a method for controlling an internal combustion engine according to the second aspect of the present invention, wherein the increase or decrease amount of ice in the junction is predicted in the environmental state determination step. The area based on the temperature of the intake air and the temperature of the blow-by gas, or the area based on the temperature of the intake air, the speed of the vehicle, and the state of the speed of the vehicle generates frost. It is determined whether it is a region, a water generation region where water droplets are generated, or a dry region where frost and water droplets are not generated, and an increase amount of ice in the junction according to the duration in the determined region Or it is the control method of an internal combustion engine which estimates the amount of decrease.

In the third aspect of the invention, it is determined whether the region is a frost generation region, a water generation region, or a dry region, and the amount of ice increase or decrease in the junction is determined according to the duration in the determined region. Further, it can be predicted more appropriately.

Next, a fourth invention of the present invention is a method of controlling an internal combustion engine according to any one of the first to third inventions , wherein the forced blowby gas temperature increasing step includes the internal combustion engine. The control method of the internal combustion engine increases the fuel injection amount into the combustion chamber and delays the ignition timing in the combustion chamber, or increases the fuel injection amount into the internal combustion engine and decreases the intake air amount into the combustion chamber.

In the fourth aspect of the invention, it is possible to appropriately realize control for increasing the temperature of the blow-by gas without increasing the output of the internal combustion engine.

Next, a fifth aspect of the present invention is a method for controlling an internal combustion engine according to any one of the first to fourth aspects, wherein the speed of the vehicle is equal to or higher than a predetermined speed. Or when the load of the said internal combustion engine is more than predetermined load, it is the control method of an internal combustion engine which temporarily suspends execution of the said forced blowby gas temperature rise step.

In the fifth aspect of the invention, when it is determined that the forced blowby gas temperature increase step should not be executed, the forced blowby gas temperature increase step is temporarily suspended to ensure higher safety. be able to.

Next, a sixth aspect of the present invention, in the control apparatus for suppressing internal combustion engine in that the go ice deposited by blow-by gas is returned to the internal combustion engine to control the internal combustion engine mounted on a vehicle, wherein An internal combustion engine control apparatus that controls the internal combustion engine using the control method for an internal combustion engine according to any one of Items 1 to 5 to suppress ice from being accumulated by the blow-by gas.

According to the sixth aspect of the present invention, it is possible to suppress the accumulation of ice generated at the junction of the new intake air and the blow-by gas with a simpler configuration without causing a problem of mountability. A control device for an internal combustion engine can be realized.

It is a control system schematic diagram explaining the input and output of the control device of an internal combustion engine. It is a flowchart explaining the example of the process sequence of the control apparatus in 1st Embodiment. It is a figure explaining the example of the intake-air temperature-blow-by-gas temperature characteristic in 1st Embodiment. It is a figure explaining an example, such as a mode that ice is accumulated according to progress of time, a mode that deposited ice is thawed. It is a flowchart explaining the example of the process sequence of the control apparatus in 2nd Embodiment. It is a figure explaining the example of the intake air temperature-vehicle speed characteristic in 2nd Embodiment. It is a figure explaining the example of the intake-air temperature-ice generation amount characteristic in 2nd Embodiment.

EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated using drawing.
● [Input / output of peripheral equipment and control device of internal combustion engine (Fig. 1)]
First, the input / output of peripheral devices of the vehicle internal combustion engine 1 and the control device 40 (corresponding to control means) will be described with reference to FIG.
The engine body 10 of the internal combustion engine 1 is a diesel engine, for example, and the rotation of the output shaft of the engine body 10 is changed by the transmission 20.
The internal combustion engine 1 is provided with, for example, a turbocharger 30. The structure on the intake passage side of the internal combustion engine 1 is not shown in the figure, which is arranged from the upstream side in the middle of an air cleaner (not shown), an upstream intake pipe 31A, a compressor of the turbocharger 30, a downstream intake pipe 32A, and a downstream intake pipe 32A. It consists of a throttle valve (teasel throttle). The upstream side intake pipe 31A and the downstream side intake pipe 32A constitute an intake pipe. The structure on the exhaust passage side of the internal combustion engine 1 includes an upstream exhaust pipe 32B, a turbine of the turbocharger 30, a downstream exhaust pipe 31B, and an exhaust aftertreatment device (not shown) from the upstream side. Exhaust gas from the engine body 10 is discharged to the upstream side exhaust pipe 32B to rotate and drive the turbine impeller 33B, and to rotate and drive the compressor impeller 33A connected to the turbine impeller 33B. The compressor impeller 33A compresses the air sucked from the upstream side intake pipe 31A and supplies the compressed air to the engine body 10 via the downstream side intake pipe 32A. The turbocharger 30 includes a variable valve mechanism (not shown).
In the engine body 10, when the pressure in the combustion chamber rises during the combustion stroke, a small amount of half-burning gas in the middle of combustion leaks into the crankcase from the gap between the piston and the cylinder, etc., and this leaked half-burning gas Some blow-by gas is accumulated in the engine body 10.
A blow-by gas pipe 12 for returning the blow-by gas accumulated in the engine body 10 to the upstream side intake pipe 31A and burning it is connected so as to communicate the inside of the engine body 10 and the upstream side intake pipe 31A. .

The upstream intake pipe 31A is provided with intake air temperature detection means 51 capable of detecting the temperature of the intake air.
The blow-by gas pipe 12 is provided with a blow-by gas temperature detecting means 52 capable of detecting the temperature of the blow-by gas in the vicinity of the joining portion (connecting portion) with the upstream side intake pipe 31A. In the first embodiment, which will be described later, the blow-by gas temperature detecting means 52 is required, but in the second embodiment, the blow-by gas temperature detecting means 52 is not particularly required.
Detection signals from the intake air temperature detection means 51 and the blow-by gas temperature detection means 52 are input to the control device 40, and the control device 40 can detect the temperature of the air sucked from the upstream intake pipe 31A and the temperature of the blow-by gas. It is.
The control device 40 is connected to an alarm means 53 such as a lamp or a buzzer, and can output an alarm to a driver who is driving a vehicle on which the internal combustion engine 1 is mounted.
The control device 40 is connected with various detection means such as a throttle opening degree detection means and a crank angle detection means (not shown), detects the operating state of the internal combustion engine 1, and determines the fuel based on the detected operating state. An injection amount, a fuel injection timing, and the like are calculated, and the injector 71 is controlled to inject the fuel of the injection amount calculated at the calculated injection timing.

Moreover, when PCV72 which is a valve which controls opening and closing of blowby gas piping is provided in the blowby gas piping 12, the signal which controls the PCV valve 72 is output from the control apparatus 40, However, The PCV valve 72 may be abbreviate | omitted. The blow-by gas pipe 12 and the PCV valve 72 constitute blow-by gas recirculation means.
The control device 40 also includes vehicle speed detection means 56 that can detect the speed of the vehicle, gear speed detection means 55 that can detect a gear position when the transmission 20 is a manual transmission, and gear speed information when the transmission 20 is an automatic transmission. An input signal from the output AT controller 60 is used in a second embodiment described later, but is not particularly necessary in the first embodiment described later.

[Processing procedure and operation of the first embodiment (FIGS. 2 to 4)]
Next, the processing procedure and operation of the first embodiment by the control device 40 will be described with reference to FIGS. In the first embodiment, the control device 40 uses the input signals from the intake air temperature detecting means 51 and the blow-by gas temperature detecting means 52 in FIG. 1 to use the vehicle speed detecting means 56 and the gear position detecting means 55 (or the AT controller 60). No special input signal is required.
The process of the flowchart shown in FIG. 2 is executed by the control device 40 at predetermined time intervals, for example. Hereinafter, the process of the flowchart shown in FIG. 2 will be described. Note that a program for executing the following processing is stored in advance in the storage unit of the control device 40.

The control device 40 detects the environmental state of the internal combustion engine 1 in step S10, and proceeds to step S20. In this case, the control device 40 detects the intake air temperature of the upstream intake pipe 31A based on the detection signal from the intake air temperature detection means 51, and in the blowby gas pipe 12 based on the detection signal from the blowby gas temperature detection means 52. The temperature of the blow-by gas at the position immediately before the junction with the upstream side intake pipe 31A is detected.
In step S20, control device 40 predicts the amount of ice increase or ice decrease at the junction of blow-by gas pipe 12 and upstream side intake pipe 31A based on the detected environmental state, and proceeds to step S30. .
For example, the storage means of the control device 40 stores the intake air temperature-blowby gas temperature characteristics shown in FIG. The control device 40 determines whether the detected state of the intake air temperature and the blow-by gas temperature corresponds to the region A, the region B, or the region C based on the intake air temperature-blow-by gas temperature characteristic, The amount of ice increase or decrease is predicted according to the determined area and the duration in that area.
In addition, area | region C is a frost generation | occurrence | production area | region where frost generate | occur | produces in a confluence | merging part. Predict the amount of ice increase over time.
Further, the region B is a water generation region where water droplets are generated at the junction. When the control device 40 determines that the state of the intake air temperature and the blow-by gas temperature corresponds to the region B, the duration corresponding to this region B The amount of ice increase will be predicted accordingly.
In addition, the region A is a dry region where no frost or water droplets are generated at the junction, and the control device 40 continues to correspond to the region A when it is determined that the state of the intake air temperature and the blowby gas temperature corresponds to the region A. Predict the amount of ice loss over time.

In step S30, the control device 40 predicts the ice generation amount (cumulative generation amount) by accumulating the ice increase amount or the decrease amount predicted in step S20, and proceeds to step S40. Note that the amount of ice produced is zero or more, and when the amount of decrease is accumulated, zero is the lower limit.
In step S40, control device 40 determines whether or not the ice-melting operation mode (corresponding to a forced blow-by gas temperature increasing step) is currently being executed. When the ice-free operation mode is being executed (Yes), the process proceeds to step S50A, and when the ice-free operation mode is not being executed (No), the process proceeds to step S50B.
When it progresses to step S50A, the control apparatus 40 determines whether the production amount of ice is more than a 1st predetermined amount. When the ice generation amount is equal to or greater than the first predetermined amount (Yes), the process proceeds to step S60, and when the ice generation amount is less than the first predetermined amount (No), the process proceeds to step S80A.
When the process proceeds to step S50B, the control device 40 determines whether or not the amount of ice generated is greater than or equal to a second predetermined amount that is greater than the first predetermined amount (second predetermined amount> first predetermined amount, see FIG. 4). Determine whether or not. When the ice generation amount is equal to or greater than the second predetermined amount (Yes), the process proceeds to step S60, and when the ice generation amount is less than the second predetermined amount (No), the process proceeds to step S80A.
Steps S10 to S50A and S50B described above correspond to the environmental state determination step.

When it progresses to step S60, the control apparatus 40 determines whether it can transfer to ice-melting operation mode. For example, the control device 40 obtains the load of the internal combustion engine 1 from the output rotational speed of the internal combustion engine 1, the throttle opening, etc., and determines whether or not the obtained load is equal to or less than a predetermined load. Alternatively, the control device 40 detects the speed of the vehicle and determines whether or not the detected speed of the vehicle is equal to or lower than a predetermined speed (note that the vehicle speed detection means 56 is required when the speed of the vehicle is used). .
If it is determined that the transition to the ice-breaking operation mode is possible (the load is equal to or lower than the predetermined load, or the vehicle speed is equal to or lower than the predetermined speed) (Yes), the process proceeds to step S80C, and it is determined that the transition to the ice-breaking operation mode is not possible. In the case (No), the process proceeds to step S70.
When the process proceeds to step S70, the control device 40 determines whether or not the ice generation amount is equal to or greater than a third predetermined amount that is greater than the second predetermined amount (third predetermined amount> second predetermined amount, see FIG. 4). Determine whether or not. When the ice generation amount is equal to or greater than the third predetermined amount (Yes), the process proceeds to step S80B, and when the ice generation amount is less than the third predetermined amount (No), the process proceeds to step S80A.

When the process proceeds to step S80A, the control device 40 cancels the ice-melting operation mode, returns to normal control, stops the output of the alarm from the alarm unit 53, and ends the process.
When the process proceeds to step S80B, the control device 40 cancels the ice-melting operation mode, returns to normal control, outputs an alarm from the alarm means 53, and notifies the driver that ice accumulation is progressing. To finish the process.
When the process proceeds to step S80C, the control device 40 executes the ice-melting operation mode, stops the alarm output from the alarm means 53, and ends the process. In addition, when performing ice-melting operation mode, the control apparatus 40 raises the temperature of blow-by gas, without increasing the output of the internal combustion engine 1. FIG. The ice-melting operation mode executed in step S80C corresponds to a forced blow-by gas temperature increasing step.
For example, in the case of a diesel engine, the control device 40 forcibly increases the fuel injection amount from the injector 71 in FIG. 1 and forcibly delays the fuel injection timing to delay the ignition timing in the combustion chamber. Alternatively, the control device 40 forcibly increases the fuel injection amount from the injector 71 and forcibly decreases the intake air amount into the combustion chamber (for example, controls the variable valve of the turbocharger 30 to force the boost pressure). ).
In the case of a gasoline engine controlled by the stoichiometric air-fuel ratio, for example, by controlling the throttle opening to forcibly increase the intake air amount to increase the fuel injection amount and forcibly delay the ignition timing for combustion Delay ignition timing in the room.

An example of the execution of the above control is shown in FIG.
In the period up to time T1, when the controller 40 determines that the state of the intake air temperature and the blow-by gas temperature is the region B (water generation region) or the region C (frost generation region) shown in FIG. The amount of ice produced is increased by accumulating the amount of increase determined according to the above. For example, in the case of the point P1 in FIG. 3, the generation amount of ice is increased.
When it is determined that the ice generation amount has become the second predetermined amount or more at time T1 and it is determined that the control device 40 can shift to the ice-breaking operation mode, the control device 40 starts executing the ice-breaking operation mode. The temperature of the blow-by gas is increased without increasing the output of the internal combustion engine 1. In this case, for example, the state changes from point P1 to point P2 in FIG.
When the control device 40 determines that the temperature of the blow-by gas is raised and is in the region A (dry region) shown in FIG. 3, the amount of ice generated is reduced by accumulating the amount of decrease determined according to the duration time. Let As a result, the amount of ice produced decreases from time T1 to time T2 in FIG.
If it is determined at time T2 that the ice generation amount has become less than the first predetermined amount, the control device 40 cancels the execution of the ice-breaking operation mode and returns to normal control of the internal combustion engine. In this case, for example, the state changes from point P2 to point P1 in FIG.
Then, the control device 40 increases the ice generation amount again during the period from time T2 to time T3. However, if it is determined at time T3 that the ice generation amount has exceeded the second predetermined amount, the control device 40 If it is determined that the ice operation mode cannot be entered, the execution of the ice operation mode is temporarily suspended. The state of FIG. 4 shows an example in which it is determined that the transition to the ice-breaking operation mode is not possible after time T3.
When the ice-breaking operation mode is kept on hold and the amount of ice produced exceeds the third predetermined amount at time T4, the control device 40 outputs an alarm from the alarm means 53 after time T4, and the driver Call attention to.

[Processing procedure of the second embodiment (FIGS. 5 to 7)]
Next, the processing procedure of the second embodiment by the control device 40 will be described with reference to FIGS. In the second embodiment, the control device 40 uses the input signals from the intake air temperature detecting means 51, the vehicle speed detecting means 56, and the gear position detecting means 55 (or the AT controller 60) in FIG. The input signal from 52 is not particularly required. Usually, the intake air temperature detecting means 51, the vehicle speed detecting means 56, and the gear position detecting means 55 (or the AT controller 60) are already provided in many cases, so that it is not necessary to provide new detecting means.
In the process of the flowchart shown in FIG. 5 which is the process procedure of the second embodiment, steps S10 to S24A and S24B are changed with respect to the process of the flowchart of the first embodiment shown in FIG. The points are different, and the same is true after step S30.
Hereinafter, differences from the first embodiment will be mainly described.

The controller 40 detects the environmental state of the internal combustion engine 1 in step S10, and proceeds to step S22. In this case, the control device 40 detects the intake air temperature of the upstream side intake pipe 31A based on the detection signal from the intake air temperature detection means 51, detects the vehicle speed based on the detection signal from the vehicle speed detection means 56, In the case of an MT vehicle, the gear position is detected based on a detection signal from the gear position detecting means 55, and in the case of an AT vehicle, the gear position is detected based on gear speed information input from an AT controller.
In step S22, control device 40 determines whether or not the ice-melting operation mode is being executed. When the ice-free operation mode is being executed (Yes), the process proceeds to step S24B, and when the ice-free operation mode is not being executed (No), the process proceeds to step S24A.
When the process proceeds to step S24B, the control device 40 predicts the amount of ice decrease due to the ice melting operation mode, and then proceeds to step S30. For example, the amount of ice reduction is set according to the duration of the ice-breaking operation mode.

When the process proceeds to step S24A, the controller 40 uses the map shown in the example of FIG. 6 or FIG. 7 to increase the amount of ice or decrease the ice at the junction of the blow-by gas pipe 12 and the upstream side intake pipe 31A. Is advanced to step S30.
For example, the storage means of the control device 40 stores the intake air temperature-vehicle speed characteristics shown in the examples of FIGS. 6A and 6B for each gear position (examples of FIGS. 6A and 6B). In this example, the example of the gear stage = 6th speed and the gear stage = 5th speed are shown, and the example of the gear stage = 4th speed to 1st speed is omitted). Each intake air temperature-vehicle speed characteristic shows each region such as region A, region B, region C1, and region C2. For example, the region A is a dry region, and when the intake air temperature, the vehicle speed, and the shift speed state continue for n1 [minutes] in this region A, it is predicted that the amount of ice is reduced by m1 [g]. Further, for example, the region B is a water generation region, and when the intake air temperature, the vehicle speed, and the shift speed state continue for n1 [minutes] in this region B, it is predicted that the amount of ice increases by m2 [g]. To do. Further, for example, the region C1 is a (mild) frost generation region, and when the intake air temperature, the vehicle speed, and the shift speed state continue in this region C1 for n1 [minutes], the amount of ice increase in m3 [g] Predict that Further, for example, the region C2 is a (severe) frost generation region, and m4 [g] (m4> m3) when the intake air temperature, the vehicle speed, and the shift speed state continue for n1 [minutes] in this region C2. The amount of ice is expected to increase.

Further, instead of the intake air temperature-vehicle speed characteristic shown in the example of FIG. 6, the storage means of the control device 40 stores the intake air temperature-ice generation amount characteristic shown in FIG. 7 so as to predict the increase or decrease of ice. It may be. In the intake air temperature-ice generation amount characteristic shown in FIG. 7, graph lines for the respective shift speeds and the vehicle speed are set. For example, the graph line G4n is a graph line with a shift speed = 4 and vehicle speed = 50 [km / h], and the graph line G5n is a graph line with a shift speed = 5 and a vehicle speed = 60 [km / h]. A line G6n is a graph line with the gear stage = 6th speed and the vehicle speed = 80 [km / h].
In the intake air temperature-ice generation amount characteristic, graph lines of various speeds (for example, 10, 20, 30 [km / h]) at each gear stage (1st to 6th speeds) are set. The ice generation amount can be obtained from the intake air temperature, the gear position, and the vehicle speed. In the intake air temperature-ice generation amount characteristic shown in FIG. 7, if the region where the ice generation amount is above 0 continues for a predetermined time, the amount of ice increase is obtained, and the region below 0 continues for a predetermined time. If so, a decrease in ice is required.
Note that the intake air temperature-ice generation amount characteristic for each gear position may be stored, and a graph line for each speed may be set for each intake temperature-ice generation amount characteristic.
In the second embodiment, as in the first embodiment, steps S10 to S50A and S50B correspond to an environmental state determination step.
In addition, since the process after step S30 is the same as that of 1st Embodiment, description is abbreviate | omitted.

  As described above, in the processing procedure (control method) of the control device 40 (corresponding to the control means) described in the first embodiment, what is newly added is a relatively small blow-by gas temperature detection means. In the processing procedure (control method) of the control device 40 (corresponding to the control means) described in the second embodiment, there is no particular need for addition. Therefore, it is possible to appropriately suppress the ice generated at the junction of the new intake air and the blow-by gas from being accumulated with a simpler configuration without causing the problem of the mountability.

The internal combustion engine control method and internal combustion engine control apparatus of the present invention are not limited to the configuration, structure, processing, operation, and the like described in the present embodiment, and various modifications and additions are possible without departing from the scope of the present invention. Can be deleted.
Further, the above (≧), the following (≦), the greater (>), the less (<), etc. may or may not include an equal sign.
The numerical values used in the description of the present embodiment are examples, and are not limited to these numerical values.
Further, the control executed in the forced blow-by gas temperature increasing step is not limited to the control described in the present embodiment.

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 10 Engine main body 12 Blow-by gas piping 20 Transmission 30 Turbocharger 31A Upstream intake pipe 32A Downstream intake pipe 40 Control device (control means)
51 Intake air temperature detection means 52 Blow-by gas temperature detection means 53 Alarm means 55 Shift speed detection means 56 Vehicle speed detection means 60 AT controller 71 Injector 72 PCV valve

Claims (6)

An intake pipe is connected to the internal combustion engine,
The intake pipe is connected to a blow-by gas pipe for recirculating blow-by gas to the internal combustion engine,
In a control means for controlling the operating state of the internal combustion engine,
An environmental state determination step for determining whether or not an environment state in which ice is generated at a junction between the blow-by gas pipe and the intake pipe based on at least the temperature of the intake air sucked from the intake pipe;
When it is determined that the environment state in which ice is generated, the forced blowby gas temperature increasing step for changing the operation state of the internal combustion engine so that the temperature of the blowby gas increases ,
In the environmental state determination step, the amount of ice generation is calculated by predicting the amount of ice increase or decrease in the merging portion based on at least the temperature of the intake air and accumulating the amount of ice increase or decrease predicted. Predicting and determining that the predicted amount of ice generation is greater than or equal to a predetermined amount is an environmental state in which ice is generated.
A method for controlling an internal combustion engine. A control method for an internal combustion engine according to claim 1 ,
In the environmental state determination step, when the amount of ice increase or decrease in the junction is predicted, the temperature of the intake air and the temperature of the blow-by gas, or the temperature of the intake air, the speed of the vehicle, and the vehicle Prediction based on the gear stage,
A method for controlling an internal combustion engine. A control method for an internal combustion engine according to claim 2 ,
In the environmental state determination step, when predicting an increase or decrease in ice in the junction, a region based on the temperature state of the intake air and the temperature of the blow-by gas, or the temperature of the intake air and the vehicle The region based on the speed of the vehicle and the state of the speed of the vehicle is a frost generation region where frost is generated, a water generation region where water droplets are generated, or a dry region where frost and water droplets are not generated And predicting the amount of ice increase or decrease in the junction according to the duration in the determined area,
A method for controlling an internal combustion engine. A control method for an internal combustion engine according to any one of claims 1 to 3 ,
In the forced blow-by gas temperature increasing step, the fuel injection amount to the internal combustion engine is increased and the ignition timing in the combustion chamber is delayed, or the fuel injection amount to the internal combustion engine is increased and the intake air amount to the combustion chamber is increased. Decrease,
A method for controlling an internal combustion engine. A control method for an internal combustion engine according to any one of claims 1 to 4 ,
When the speed of the vehicle is equal to or higher than a predetermined speed, or when the load of the internal combustion engine is equal to or higher than a predetermined load, the execution of the forced blow-by gas temperature increasing step is temporarily suspended.
A method for controlling an internal combustion engine. In a control device for an internal combustion engine that controls an internal combustion engine mounted on a vehicle and suppresses accumulation of ice by blow-by gas returned to the internal combustion engine.
Controlling the internal combustion engine using the method for controlling an internal combustion engine according to any one of claims 1 to 5 to prevent ice from being accumulated by the blow-by gas.
Control device for internal combustion engine.

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